4(3-Carboxy-4-hydroxyphenylazo)-benzenlsulphonamide pyridine compounds having immunosuppressive effects

ABSTRACT

The compound:   where A is either (1)   WHERE R1; R2 and R3 are either hydrogen, lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamide and R4 is either lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamide, or (2)   where R1&#39;&#39;; R2&#39;&#39;; R3&#39;&#39; and R4&#39;&#39; are either hydrogen, lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamido. These compounds are useful in immunosuppressives especially in skin transplants.

United States Patent Agback et al.

[451 Oct. 28, 1975 4(3-CARBOXY-4-HYDROXYPHENYLAZO)- BENZENLSULPHONAMIDE PYRIDINE COMPOUNDS HAVING IMMUNOSUPPRESSIVE EFFECTS [75] Inventors: Karl Hubert Agback, Uppsala;

Ragnvald Erik Lindblom, Almunge, both of Sweden [73] Assignee: Pharmacia Aktiebolag, Uppsala,

Sweden 22 Filed: Nov. 20, 1972 21 Appl.No.:307,903

[30] Foreign Application Priority Data Primary Examiner-Floyd D. Higel Attorney, Agent, or Firm-Fred Philpitt [5 7] ABSTRACT The compound: Coo" where A is either (1) where R,; R and R are either hydrogen, lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamide and R is either lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamide, or (2) where R,'; R R and R are either hydrogen, lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamido.

These compounds are useful in immunosuppressives especially in skin transplants.

16 Claims, No Drawings 4(3-CARBOXY4-HYDROXYPHENYLAZO)-BEN- ZENLSULPHONAMIDE PYRlDlNE COMPOUNDS HAVING IMMUNOSUPPRESSIVE EFFECTS These compounds are useful as immunosuppressives especially in skin transplants The novel pyridine derivatives are compounds of the general formula I /coon where A is a group having the formula ll in which R R and R are each hydrogen or lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamido and R is lower alkyl, halogen, lower alkoxy, cyano, nitro or carboxamido, or A is a group having the formula Ill (lll) A NH where A has the aforementioned significance, is reacted with a compound of the formula V where Z, is a group capable of being converted to a carboxy group and Z is a hydroxy group or a group capable of being converted to a hydroxy group, Z, and Z optionally being linked together, and Y is halogen, preferably chloro, whereupon the obtained compound of the formula Vl where A; Z, and Z have the aforementioned significance, is treated to convert the group Z, to a carboxy group and 2 to a hydroxy group when Z is a group capable of being converted to a hydroxy group.

In the majority of cases, the reaction of the compound of the formula IV with the compound of the formula V can be effected in the presence of an acid binding agent, preferably an organic tertiary amine or a basic heterocyclic compound, such as pyridine. for example. The reaction process can also be effected in the presence of an excess of the compound lV, which then functions as the acid binding agent. The reaction is preferably effected in the presence of an organic solvent, e.g., pyridine. The obtained compound of the formula VI can be subjected to oxidation or hydrolysis for the purpose of converting the group Z, to a carboxy group, and optionally to a hydrolysis for converting the group Z to a hydroxy group,

2, is preferably a group which is inert under the reaction conditions used during the reaction process, but which later can be converted to a carboxy group. As an example of such groups can be mentioned the group COOR,

where R is alkyl,

where R and R are hydrogen or alkyl or together alkylene,

where R R and R, are alkyl, aryl, or CN, all of which can be converted to COOH by alkaline or acid hydrolysis.

Other examples of groups which can be converted to carboxy groups are CHO, CH OH, CH OR, where R is alkyl or aryl,

where R and R,, are alkyl or aryl, capable of being converted to carboxy groups by oxidation processes.

The following are examples of groups Z capable of I being converted to OH:

where R and R are hydrogen, alkyl or aryl and R are alkyl or aryl, R and R being optionally linked together,

where R is hydrogen, alkyl or aryl and R and R are alkyl or aryl, R and R being both aryl when R, is hydrogen, which groups are capable of being converted into a hydroxy group by means of acid hydrolysis. Z is preferably the groups -OCOR or O SO R, where R is alkyl or aryl, said groups being capable of being converted to a hydroxy group by means of alkaline hy drolysis.

Z, and Z may optionally be linked together. As an example of the residue where Z, and Z are linked together, can be mentioned:

where R is hydrogen, alkyl or aryl,

c.H @ij where R is hydrogen, alkyl or aryl, and

where R R, and R are hydrogen, alkyl or aryl. These groups can be converted to salicyclic acid residues by hydrolysis, preferably alkaline hydrolysis.

In accordance with an alternate method, the novel compound I can be prepared by a method which is characterized in that a compound of the formula VI] where A has the aforementioned significance, is diazotized, preferably by treatment with nitrous acid, in an aqueous environment, whereafter the obtained diazonium salt is reacted with a compound of the formula Vlll H (Vlll) where Z is carboxy or a group capable of being converted to a carboxy group, preferably carboxy, and in an alkaline aqueous environment, whereafter the compound of the formula IX where A and Z, have the aforementioned significance, is treated to convert the group to the carboxy group when Z is a group capable of being converted to a carboxy group. The conversion is normally effected with an oxidizing or hydrolysing agent.

The invention also embraces those cases in the aforementioned different embodiments of the general method in which the groups Z, and Z; are converted, preferably converted to the carboxy and/or hydroxy group under the differing reaction conditions.

The novel compounds of the present invention have valuable biological properties and good physiological acceptability.

The novel compounds present significant immunosuppressive effects as opposed to the known compound 2-[4-(4-hydroxy-3-carboxy-phenylazo)-benzene sulphonamido1-pyridine.

It is known that test animals subjected to skin transplantations, where the transplants originate from another strain within the same species, reject these transplants after a certain period of time. This rejection of the transplanted skin can be delayed for a certain length of time by treating the animals with an active immunosuppressive substance. The following table illustrates the increased survival time for the transplant on mice treated with different substances in comparison 'with untreated mice. Each result is the mean value obtained from 10 treated and 10 untreated animals. The

letter A in the table signifies the aforementioned drug substance 2-[4-(4-hydroxy-3carboxy-phenylazo) benzene sulphonamidol-pyridine.

TABLE Desig- Formula or name lncreased sur- Statistical nation vival time in significance calendar days A Salicylazosulpha- 1.3 no

pyridine CH B l 6.2 yes N S u C 4.0 ycs N S u D I 5.l yes N S U F I E 2.3 yes c N S u F i 5.) yes J N S u G I I 2.9 yes N S u 2.4 yes COOH The effects are judged to be statistically significant if the confidence coefficient is greater than 0.95. The dosages administered comprise 500 mg per kg body weight and were given daily during the test period.

It is reported in Swedish patent 130 524 that the compound 2-[4-(4-hydroxy-3carboxy-phenylazo)- benzene sulphonamido1-pyridine has an antibacterial effect. None of the novel compounds of the invention showed antibacterial activity during any of the tests carried out.

The novel compounds are thus potential therapeutical agents for use in organ transplants and for treating autoimmuno diseases.

EXAMPLE I 2-[4-( 3carboxy-4-hydroxy-phenylazo)-benzenesulphonamido13-methyl pyridine a. 36.4 grams of 4-(4-acetoxy-3 carbomethoxyphenylazo)-benzene sulphonylchloride, 10 grams of 2- amino-3-methyl pyridine and ml of pyridine were mixed and stirred for 3.5 hours. The solution was emptied onto ice and hydrochloric acid. The crystalline product was filtered off and washed with water. The product was then hydrolysed with diluted sodium hydroxide and acidified, whereafter the product was filtered off and dried.

Melting point 253C with decomposition.

b. 20 g of 4-(4-acetoxy-3carbomethoxy-phenylazo)- benzene sulphonylchloride, ll g of 2-amino-3-methyl pyridine and ml of toluene were mixed and stirred for 2.5 days. The toluene solution was admixed with diluted sodium hydroxide and the mixture heated to azeotropically distill the toluene. The residual aqueous solution was then acidified. The product was filtered off and dried.

Melting point 252C with decomposition.

c. 5.25 g of 2-(4-amino benzene-sulphonamido)-3- methyl-pyridine were dissolved in a mixture of 16.5 ml of water and 5 ml of concentrated hydrochloric acid. The solution was cooled to 0C, whereafter a solution of 1.45 g of sodium nitrite in 10 ml of cold water was added while stirring and cooling. After 10 minutes, the reaction mixture was transferred to a vessel containing a cold solution of 3.0 g of salicyclic acid, 4.1 g of sodium hydroxide in 20 ml of water. The obtained mixture was filtered off and the filtrate acidified in a cold environment with hydrochloric acid. The obtained product was recrystallized from dilute alcohol, the title substance being obtained thereby.

EXAMPLE 2 2-[4-( 3carboxy-4-hydroxy-phenylazo )-benzenesulphonamido]4-methyl-pyridine 16 g of 4-(4-acetoxy-3-carbomethoxyphenylazo)- benzene sulphonyl chloride, 4.6 g of 2-amino-4-methyl pyridine and 40 ml of pyridine were mixed and stirred for 2 hours. The process was then continued as described in Example 1 (a) above.

Melting point 270C with decomposition.

EXAMPLE 3 2- 4-( 3 -carboxy-4 hydroxy-phcnylazo )-benzene sulphonamido]5-methyl-pyridine 16 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)- benzenesulphonyl chloride, 4.6 g of 2-amino-5-methyl pyridine and 35 ml of pyridine were mixed and stirred for 2 hours. The process was then continued in accordance with Example 1 (a) above.

Melting point 252C with decomposition.

EXAMPLE 4 2[4-( 3carboxy-4-hydroxy-phenylazo)benzenesulphonamido]-6-methyl-pyridine 16 g of 4-(4-acetoxy-3carbomethoxy-phenylazo)- benzcnesulphonylchloridc, 4.6 g of 2-amino-6-methyl pyridine and 35 ml of pyridine were mixed and stirred for 2 hours. The process was then continued according to Example .1 a) above.

Melting point 252C with decomposition.

EXAMPLE 2-[4-( 3-carboxy-4-hydroxy-phenylazo )-benzenesulphonamido]-4,6-dimethy1-pyridine 4 g 4-(4-acetoxy-3-carbomethoxy-phenylazo)-benzene-sulphonyl chloride, 1.3 g of 2-amino-4,6-dimethyl pyridine and 20 ml pyridine were mixed and stirred for 3 hours. The process was then continued in accordance with Example 1 a) above.

Melting point 257C with decomposition.

EXAMPLE 6 2-[4-( 3-carboxy-4-hydroxy-phenylazo )-benzenesulphonamidol-5-chloro-pyridine.

16 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)- benzenesulphonyl chloride, 5.3 g of 2-amino-5- chloropyridine and 50 ml of pyridine were mixed and stirred. The process was then continued in accordance with Example 1 a) above.

Melting point 257 259C with decomposition.

EXAMPLE 7 2-[4-( 3-carboxy-4-hydroxy-phenylazo)-benzenesulphonamidol-3 ethyl-pyridine 16 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)- benzenesulphonyl chloride, 5 g of 2-amino-3-ethyl pyridine and 50 ml of pyridine were mixed and stirred for 3 hours. The process was then continued in accordance with Example 1 a) above.

Melting point 233 235C with decomposition.

EXAMPLE 8 2-[4-( 3-carboxy-4-hydroxy-phenylazo )-benzenesulphonamido -3-ethoxypyridine 20 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)- benzenesulphonyl chloride, 8 g of 2-amino-3-ethoxy pyridine and 100 ml of pyridine were mixed and stirred for 3 hours. The process was then continued in accordance with Example 1 (a) above.

The melting point was 214 216C with decomposition.

EXAMPLE 9 2-[4-( 3-carboxy-4-hydroxy-phenylazo )-benzenesulphonamido]-3-chloro pyridine 50 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)- benzenesulphonyl chloride, 17 g of 2-amino-3- chloropyridine and 150 ml of pyridine were mixed and stirred for 4 hours. The process was then continued in accordance with Example 1 a) above.

Melting point 240 242C with decomposition.

EXAMPLE 1O 3-[4-( 3-carboxy-4-hydroxy-phenylazo )-be'nzene-sulphonamido]-2,6-dimethyl pyridine 16.8 g of 3-(4-amino-benzenesulphonamido)-2,6 dimethyl pyridine were dissolved in a mixture of 50 ml of water and ml of concentrated hydrochloric acid and chilled to 0C. A solution of 4.3 g of sodium nitrite in 25 ml water was added with cooling. After 15 minutes, the reaction mixture was transferred to a vessel containing 8.9g of salicyclic acid and 12.2 g of sodium hydroxide in 60 ml of water. The obtained clear solution was acidified. After filtering the crystalline product and recrystallizing from the diluted alcohol, the title substance was obtained with a decomposition point of 270C.

EXAMPLE 11 3-[4-( 3-carboxy-4-hydroxy-phenylazo )-benzene-sulphonamido]-2chloro-pyridine 16 g of 4-(4-acet0xy-3-carbomethoxy-phenylazo)- benzenesulphonyl chloride, 5.3 g 3-amino-2- chloropyridine and 50 ml of pyridine were mixed and stirred for 3 hours. The process was then continued in accordance with Example 1 (a) above.

Melting point 237C with decomposition.

EXAMPLE 12 5-bromo-2-[ 4-(4-hydroxy-3-carboxy-phenylazo)- benzene-sulphonamido]-6-methyl-pyridine 9.4 g of 2-amino-5-bromo-6-methyl pyridine, 19.9 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)-benzenesulphonyl chloride and 50 ml of pyridine were mixed and stirred for 3 hours. The process was then continued in accordance with Example 1 a) above.

Melting point 253C with decomposition after recrystallization from a mixture of dimethylformamide and ethanol.

EXAMPLE l3 3-[4-( 3-carboxy-4-hydroxy-phenylazo)-benzenesulphonamido]-pyridine 12 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)- benzenesulphonyl-chloride, 3 g of 3-aminopyridine and 60 ml of pyridine were mixed and stirred for 6 hours. The process was then continued in accordance with Example l (a) above.

Melting point 262C with decomposition.

EXAMPLE 14 3-[4-(4-hydroxy-3-carboxy-phenylazo )-benzenesulphonamidol-6-methoxy-pyridine 36.8 g of 4-(4-acetoxy-3-carbomethoxy-phenylazo)- benzenesulphonyl chloride, 11.5 g of 3-amino-6- methoxy-pyridine and ml of pyridine were mixed while stirring for 2 hours. The process was then continued in accordance with Example 1 (a) above.

Melting point 228 230C with decomposition.

EXAMPLE l5 2-[4-( 4-hydroxy-3-carboxy-phenylazo)-benzenesulphonamido1-5-methyl-pyridine the mixture is agitated for 5 minutes at 50C. The mixture is filtered and the zinc residues are washed with ethanol. The solution is cooled to C and the solution of 8.3 g of FeCl;, 6H O, 55 ml of water and 14 ml of ethanol is added, whereupon the mixture is stirred at 0C for 90 minutes. The product is filtered off, washed with water and dried.

The obtained product, 2.6 g, 1.7 g of aminosalicyclic acid methylester and 70 ml of acetic acid are mixed and heated at 80C for 2 hours. Water is added and the mixture is cooled to C. The crystailized product is filtered off and washed with water, whereupon it is dispersed in acetone. The substance is hydrolysed with 1 N NaOH for 30 minutes at 90C. The solution is treated with charcoal, and then acidified. The mixture is cooled and the product filtered off and washed with water. The product is recrystallized from dimethylformamide and acetic acid. Melting point 252 254C.

What we claim is:

1 A 4-( 3 -carboxy-4-hydroxy-phenylazo benzenesulphonamide pyridine of the formula COOH where A is a member selected from the group consisting of (A) a group of the formula where R R and R are each a member selected from the group consisting of hydrogen, lower alkyl, halogen, lower alkoxy, cyano, nitro and carboxamido and R is a member selected from the group consisting of lower alkyl, halogen, lower alkoxy, cyano, nitro and carboxamido, and (B) a group of the formula I l R l R 2 where R,'; R R and R are each a member selected from the group consisting of hydrogen, lower alkyl, halogen, lower alkoxy, cyano, nitro and carboxamido.

2. A compound as claimed in claim 1 in the form of its pharmaceutically acceptable salt.

3. 2-[4(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-3-methyl-pyridine.

4. 2-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-4-methyl-pyridine.

5. 2-[4-(3-carboxy-4-hydroxy-phenylazo)benzene sulphonamido]-5-methyl-pyridine.

6. 2-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-6-methyl-pyridine.

7. 2-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-4,6-dimethyl-pyridine.

8. 2-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-5-chloro-pyridine.

9. 2-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-3-ethyI-pyridine.

l0. 2-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-3-ethoxy-pyridine.

ll. 2-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamidol-3-chloro-pyridine.

l2. 3-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-2,6-dimethyl-pyridine.

13. 3-[4(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido]-2-chloro-pyridine.

l4. 5-bromo-2-[4-(3-carboxy-4-hydroxy-phenylazo)- benzenesulphonamido]-6-methyl-pyridine.

15. 3-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido1-pyridine.

l6. 3-[4-(3-carboxy-4-hydroxy-phenylazo)-benzene 

1. A 4-(3-CARBOXY-4-HYDROXY-PHENYLAZO)-BENZENESULPHONAMIDE PYRIDINE OF THE FORMULA
 2. A compound as claimed in claim 1 in the form of its pharmaceutically acceptable salt.
 3. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-3-methyl-pyridine.
 4. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-4-methyl-pyridine.
 5. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-5-methyl-pyridine.
 6. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-6-methyl-pyridine.
 7. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-4, 6-dimethyl-pyridine.
 8. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-5-chloro-pyridine.
 9. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-3-ethyl-pyridine.
 10. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-3-ethoxy-pyridine.
 11. 2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-3-chloro-pyridine.
 12. 3-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-2,6-dimethyl-pyridine.
 13. 3-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-2-chloro-pyridine.
 14. 5-bromo-2-(4-(3-carboxy-4-hydroxy-phenylazo)-benzenesulphonamido)-6-methyl -pyridine.
 15. 3-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-pyridine.
 16. 3-(4-(3-carboxy-4-hydroxy-phenylazo)-benzene sulphonamido)-6-methoxy-pyridine. 